Is this Gibbs' most useful talent on NCIS?
Agent Leroy Jethro Gibbs is a man of many talents. He can solve mysteries, build boats, and he can move those boats out of his basement without ever properly explaining how he does it.
There are other things too. Gibbs is a famous marksman, he knows first aid and can fight hand to hand with the best. He is a loyal friend and selfless employee of the police. He is determined to hunt and slaughter his wife's killer like an animal, and then hide his crime from the law for years. Gibbs' entry on the NCIS fan wiki lists nearly two dozen awards he received during his time in the Marines. There is no way to know for sure that he is a flautist, but also no way to know for sure that he is not. That's the beauty of mystical stoicism: you can never tell what's beneath the surface.
Gibbs has a particular set of skills that have proven useful on multiple occasions. These skills do not involve violence or any mysterious elements, unlike his proficiency in shooting or his house's removable section. Despite being known for his quiet demeanor, Gibbs is actually a talented linguist.
Learning is fun with Agent Gibbs
Gibbs has demonstrated his ability to speak multiple languages in various instances. In the first season of NCIS, he was able to interpret a Mandarin tattoo on a suspect. Since then, he has been observed speaking, reading, or interpreting Japanese, Russian, and American Sign Language. Additionally, he is skilled in physically communicating with his colleagues through hitting them on the back of their heads.
Being able to speak multiple languages is an impressive skill in any profession, but it is particularly useful in the field of maritime justice where individuals from various seafaring nations may arrive unexpectedly. The origin of Gibbs' exceptional linguistic abilities is uncertain, but it could be an extension of his "never be unreachable" policy, knowledge gained during his time in the Marines, or a result of needing to hire construction companies from overseas due to repeatedly tearing down and rebuilding his basement walls to accommodate boats. Regardless of how he acquired this talent, Gibbs never ceases to amaze.